1. Field of the Disclosed Embodiments
This disclosure relates to systems and methods for remotely diagnosing and correcting for errors in wiring in an Automatic Identification System Pilot Port.
2. Related Art
The Automatic Identification System (AIS) is an automated maritime vessel tracking system used on ships for identifying and locating vessels within a vicinity of one's own vessel by electronically exchanging data with nearby vessels. The AIS augments radar and visual lookouts and is based on radio transponders that pass unique identification, position, course and speed information regarding one's own vessel and the vessels in the area of one's own vessel between the vessels.
The U.S. Coast Guard requires commercial vessels to carry AIS radios. See, e.g., 33 C.F.R. §164.46 entitled “Automatic Identification System (AIS).” This section of the Code of Federal Regulations (“Rules”) specifies, among other things, what is considered to be a proper installation for an AIS radio in a vessel. In order to determine the requirements for a proper installation, the Rules refer to a document from the International Maritime Organization entitled “Guidelines For The Installation Of A Shipborne Automatic Identification System (AIS).” See IMO SN/Circ. 227 dated Jan. 6, 2003. The IMO document provides that “[a] pilot input/output port is part of an AIS Class A station. A plug connected to this port should be installed on the bridge near the pilot's operating position so that a pilot can connect a Personal Pilot Unit (PPU).” Id. at §3.2. According to the referenced proper installation for the AIS, the Coast Guard requires vessels with an AIS radio to provide this interface to the AIS radio according to the input/output port requirements set forth in the IMO document. The standard shipboard AIS will be fitted with this pilot/auxiliary input/output port, which will allow the pilot, in his or her own workstation, to receive more frequent navigational information. In this installation, the pilot will receive all of the available AIS information and will be able to forward information to other vessels in the vicinity of the pilot's own vessel.
The port required by the Coast Guard for the AIS radio installation is a serial data interface, as defined by International Electronic Commission (IEC) International Standard 61162 (IEC 61162). This interface, which is commonly referred to as the “Pilot Port,” is used by the professional maritime pilot to obtain the information from the AIS radio for display on the individual pilot's PPU. The display then provides a situational awareness overview regarding an own vessel and for vessels in the vicinity of the own vessel.
The AIS Pilot Port is a bi-directional RS-422 (ANSI/TIA/EIA-422-b) interface. The interface consists of a first pair of balanced differential (high and low) lines for receiving information, and a second pair of balanced differential (high and low) lines for transmitting information. Errors often occur in installation of the Pilot Port on a vessel. These errors may include installers reversing the receive and transmit lines. More often, however, it is the balanced differential lines that are reversed (high for low, or low for high).
The problem of mis-wiring is an all-too-common occurrence that negatively impacts the ability of the pilot to interface with the AIS radio. An ability to detect and immediately adjust for these mis-wirings is almost a necessity. The frequency of these mis-wirings has led to mechanical solutions being attempted in which the pilot (operator) may physically and locally manipulate one or more mechanical switches in a unit that is placed between the Pilot Port and the pilot's PPU. While this approach is effective, it requires that the pilot/operator monitor the status of the data from the AIS radio and physically manipulate the switches to achieve the correct data orientation. This is undesirable because it requires a “human-in-the-loop” and is a needless encumbrance on the pilot as the pilot is performing other piloting duties.